Help! Can someone please explain how to do this?

Zad. 2 W marszobiegu chłopiec przebiegł 900 m w ciągu 205 min, a następnie przeszedł 300m w tym danym czasie. Jaka była średnia

USPshnik [31]

Odpowiedź:

0,049 m / s

Wyjaśnienie:

Biorąc pod uwagę, że:

Dystans biegu = 900m

Czas trwania = 205 minut

Długość przejścia = 300 m

Zajęty czas = 205 minut

Średnia prędkość :

(Przebieg + pokonany dystans) / całkowity czas

Średnia prędkość :

(900 m +. 300 m) / 205 + 205

1200 m / 410 minut

Minuty do sekund

1200 / (410 * 60)

1200/24600

= 0,0487804

= 0,049 m / s

8 0

2 years ago

Which graph shows an object that is dropped?

Olegator [25]

Answer:

I'm pretty sure it's the third one where velocity goes from positive to negative

Explanation:

the positive velocity is before the object hits the ground and the negative is after

8 0

3 years ago

Which one does not affect the gravitational force between the 1 point

Zinaida [17]

Answer:

D. The net electrical charge of the Earth.

Explanation:

All the other three choices affect the gravitational force. I remember from middle school.

6 0

2 years ago

A 1 170.0 kg car traveling initially with a speed of 25.000 m/s in an easterly direction crashes into the back of a 9 800.0 kg t

kykrilka [37]

Explanation:

It is given that,

Mas of the car, $m_1=1170\ kg$

Initial speed of the car, $u_1=25\ m/s$

Mass of the truck, $m_2=9800\ kg$

Initial speed of the car, $u_2=20\ m/s$

Final speed of the car, $v_1=18\ m/s$

(a) It is a case of elastic collision. Let $v_2$ is the final velocity of the truck right after the collision. Using the conservation of linear momentum to find it :

$m_1u_1+m_2u_2=m_1v_1+m_2v_2$

$v_2=\dfrac{m_1u_1+m_2u_2-m_1v_1}{m_2}$

$v_2=\dfrac{1170\times 25+9800\times 20-1170\times 18}{9800}$

$v_2=20.83\ m/s$

(b) Initial kinetic energy is given by :

$k_i=\dfrac{1}{2}(m_1u_1^2+m_2u_2^2)$

$k_i=\dfrac{1}{2}\times (1170\times (25)^2+9800\times (20)^2)$

$k_i=2325625\ J$

Final kinetic energy is given by :

$k_f=\dfrac{1}{2}(m_1v_1^2+m_2v_2^2)$

$k_f=\dfrac{1}{2}\times (1170\times (18)^2+9800\times (20.83)^2)$

$k_f=2315595.61\ J$

The change in mechanical energy of the car truck system in the collision:

$\Delta K=k_f-k_i$

$\Delta K=2315595.61-2325625$

$\Delta k=-10029.39\ J$

The loss in kinetic energy is 10029.39 Joules.

(c) The change in mechanical energy gets changed energy gets changed in the form of heat and light.

Hence, this is the required solution.

6 0

2 years ago

A person with Parkinson's disease may sometimes experience muscle tremors and difficulty initiating movements or speech. To help

Ulleksa [173]

Answer:

dopamine is used to help with Parkinson

Explanation:

D. dopamine

3 0

2 years ago